Harris



Nov. 21, 1950 c. HARRIS MAGAZINE FEED FURNACE 2 Sheets-Sheet 1 Filed Jan. 12, 1946 Nov. 21, 1950 c. HARRIS MAGAZINE FEED FURNACE Filed Jan. 12, 1946 2 Sheets-Sheet 2 an annular section or member.

Patented Nov. 21, 1950 MAGAZINE FEED FURNACE Cleo Harris, Kalamazoo, Mich., assignor to Borg- Warner Corporation, Chicago, Ill., a corporation of Illinois Application January 12, 1946, Serial N 0. 640,728

Claims.

This invention relates generally to furnaces and mor particularly to that type known as a magazine-feed furnace.

Furnaces of this type have become increasingly popular, particularly for home use, because they.

provide a magazine which needs to be charged with fuel less frequently than is necessary in charging the grate of an ordinary furnace. For example, one member of the household may fill the magazine with fuel in the morning before leaving the home and then may fill it again in the evening upon his return, or before retiring, thus freeing the other members of the household from tending the furnace during his absence. Although my invention is shown as being embodied in a warm air furnace, it will be understood that this is merely by way of example and that it is applicable to other types of heating equipment.

People who desire to replace their old furnaces with a magazine-feed furnace are frequently deterred by the expens and by the time needed to convert from one type of furnace to another since the ordinary furnace in assembled condition is too large to bring through existing doorways in the house and must therefore be brought in piece by piece and assembled thereafter. This is time consuming and is expensive because of the labor involved. Furthermore, many existing forms of magazine-feed furnaces are large and require an unnecessarily large amount of floor space. It is, therefore, an object of my invention to overcome these dil'ficulties and to do so I have invented a magazine-feed furnace which provides a large magazine, a large fuel burning space and warm air ducts having large surface areas subjected to the heat from the burning fuel but which is, nevertheless, compact and able to be moved through any standard doorway in assembled condition needing only to be connected to the proper ducts before use. To this end I have made the cross section Of the furnace substantially semicircular with the magazine, grate, combustion chamber and warm air ducts all substantially concentric and of an arcuate or semiannular cross section. By semiannular-is meant one-half of It is a further object of my. invention to provide a sturdy but light weight furnace construction and to this end I hav employed sheet metal wall portions so formed as to be readily assembled with each other to form a rigid and durable structure.

In'a magazine-feed furnace it is customary to have an air inlet positioned above the level of the coal in the magazine so that such air may filter down through the coal in the magazine and carry with it combustible gases generated from the heated coil. This mixture of air and gases passes to the area of combustion above the fuel on the grate and serves as additional fuel for heating the warm air ducts. It has been found from experimentation, however, that even in furnaces of this type employing such a down-draft through the coalin addition to the ordinary inlet under the grate-complete combustion of the solid fuel and of the combustible gases driven therefrom is not achieved.

It is, therefore, another object of my invention to provide means which will produce substantially one hundred per cent combustion of the solid fuel and of the combustible gases driven therefrom in order to provide an efiicient heating system. To accomplish this purpose I introduce air from outside of the furnace at a point above the burning fuel. The air duct introducing such secondary air is of course subjected to intense heat and is, therefore, subject to being burned out, thus necessitating frequent replacements. To make such replacements, the operation of the furnace must be interrupted. This is unsatisfactory and frequently dangerous to health and property.

It is a further object of my invention, therefore, to prevent such burning out of the duct which introduces the secondary air and to do this I have positioned such duct in heat transfer relationship with respect to one of the warm air ducts. Such construction serves a double purpose. Not only is heat withdrawn from the secondary air duct thus preventing it from burning out, but such heat is also passed on to the air in the warm air duct, thus resulting in greater heating efficiency. As a further means of preventing destruction of the secondary air duct I have constructed it of a heat resistant alloy. As will be noted hereinafter, all such portions of the secondary air inlet duct as are subjected to the burning fuel are positioned in heat transfer relationship with a Warm air duct.

It is a further object to employ a warm air passageway, having the secondary air duct secured thereto, as a retaining wall of the magazine. Such construction is not only economical but serves to so position the secondary air duct with respect to the combustion chamber and magazine that the gases driven off from the coal in the magazine and the unburned gases from the fuel on the grate are supplied with additional oxygen to thereby cause substantially complete combustion of all the fuel elements.

The foregoing and other objects and advantages will be more readily apparent from the following written description taken in connection with the drawings in which:

Fig. 1 is a front elevational view of my improved furnace;

2 is vertical section on an enlarged scale taken along the line 2-2 of Fig. l; and

Fig. 3 is a horizontal sectional view taken on the line 3-3 of Fig. 2.

Throughout the written description the same reference numerals will be employed for the some elements in the several views.

Referring now to Figs. 1, 2 and 3, reference numeral it indicates generally the casing wall which is formed of sheet steel and which has a top or bonnet 82 joined thereto by a band M. A bottom wall it is joined to the casing it) by a base ring ii. The bottom wall 16 forms the base of the ash pit IS the entrance to which is through an ash removal door 28.

In this pit collect the ashes which fall through the holes in the grate 22, said grate being semiannular in horizontal cross section and being pivoted on bolt 2% which is secured to the casing l8 through an intermediate semicircular wall portion 25. The grate 22 may be moved ai'cuately about the bolt 24 as a pivot by means of the lever 28 on the exterior of the furnace in order to shake down the ashes from the grate into the ash pit. Surrounding the semiannular grat 22 on one side is a semiannular row of fire bricks 39 which is supported on a ring 32 which is carried on a wall 34.

On the other side of the grate is a fan-shaped partition or slide 35 having a cone-like surface leading upwardly from adjacent the inner edge of the grate 22 to the door 38 for the magazine to. This partition 36 is secured at its upper end to the casing iii and at its lower edge to a semiannular plate 3'! which in turn rests on the semicircular wall portion 26 and is secured thereto by bolt 24. The door 38 may be opened for charging the magazine 58 with a suppl of fuel, such as coal, which will slide down the fanshaped partition 3t and feed onto the grate 22. As the fuel is consumed more of it slides downwardly on to the grate. A semiannular warm air duct t2 surrounds one side of the magazine id and opens upwardly into a plenum chamber as from which warm air flows upwardly through the warm air passageway 4'5 to the space to be heated. Another warm air duct 46, formed by semiannular walls 36 and 49 which are spaced radially outwardly from the grate 22, is connected with the plenum chamber. and warm air duct 42 at their respective top portions, the connections with duct Q2 being made by a cross passageway or duct 59] which passes through the fine 52.

A combustion chamber 54', formed above the grate 22 and bounded on one side by the wall 3% and fire bricks 3i), and on the other side by the fuel feeding down cone-shaped partition from the magazine 43, is positioned below and, to one side of the warm air duct 22. Smoke and other products of combustion rise through. the flue 52 and pass out through the connecting pipe 5.5 to a Smokestack (not shown). A passageway or duct 53 joins the top of the magazine and the flue 52 and is closed by a clack valve 6% which is gravity operated. Any excessive pressure or any explosion of the gases in the magazine ii? will blow open the valve 6? to permit discharge through the passageway 53 and out to the smoke- 4 stack. Flue 52 is closed oif from the warm air ducts G5 and d2 by walls 34 and 62, respectively, and from plenum chamber M by a semiannular plate 6 2 secured to walls 34 and 62 at the upper end of flue 52.

Air, for the purpose of supplying oxygen for combustion, is introduced through a damper 10 in door 2!], a damper 72 in door 38 and through a damper 76' also positioned in the front of the furnace in the casing ill. Air flows in through damper l9 and upwardly through the grate 22 while air entering through the damper l2 flows downwardly through the fuel in the magazine 40 toward the combustion chamber 54. The air passing downwardly through the magazine 40 will carry with it certain combustible gases which are driven from the coal in the magazine by reason of the heat in the furnace and they will in turn burn when they reach the combustion chamber 54.

Since, however, the supply of oxygen through dampers l9 and 12 is frequentl insuflicient for complete combustion of the solid fuel and of the combustible gases driven from the solid fuel, air is also supplied to the combustion chamber 54 above the burning fuel and at a point where the gases from the magazine ill tend to flow to the combustion chamber. This admission of mits'ici'eair, hereinafter referred to as secondary air, flows through the damper M to a passageway 'ifi' inside the front of the furnace, this passageway being connectible at its ends to a serniannula'r air duct 18. The secondary air duct i8 is preferably formed of a channel 82 of steel alloy which is heat re? sistant and has a series of air holes 84 directed downwardly toward the combustion chamber '56. The channel 82 is secured at its upper, openside to Walls T9 and 62 and over the bottom wall 86 of the warm air duct 52. The duct #3 obtains additional support from oppositely extending flanges ll of the partition 36, which flanges have notches cut in their top edges to embrace the duct 18 which is seated therein. It will be readily seen from the drawings that the secondary air duct 1-8 is. positioned in heat transfer relationship with the warm air duct 42 so that excessive heat supplied from the burning fuel is carried ofi from the duct 18 by means of the. warm air duct 42 thus preventing burning out of duct 78. It will be further noted thatthe passageway 18 leading from the damper Hi to either end of the semi-annular duct 78 is, not positioned in the combustion chamber. But all portions of the secondary air inlet duct T8 which are directl exposed to the heat of the combustion chamber are positioned on the under side of the warm air duct 42.

Since the grate and the combustion chamber are semiannular, a large area is provided for burning the fuel. Yet, the depth of the furnace from the front to the back side thereof is such that the furnace in its assembled condition may be passed through an ordinary doorway in a private home or other building. This is advantageous since it eliminates the necessity of carrying in portions of the. furnace and as sembling them within the building which as sembly is time consuming and expensive. My furnace may be constructed at the factory and shipped as a unit for immediate installation by simply connecting the bonnet [2 to the warm air duct 45 leading to the space to be heated, connecting the cold air return duct 88 to the casing IB, and connectin pipe 56 to the smokestack.

As previously pointed out, the warm air duct #2 and the secondary air duct 78 together serve to form a wall portion of the magazine 48. Such construction is economical and saves space since otherwise an additional baiile or wall would be necessary for retaining the coal in the maga zine.

From the foregoing it will be seen that I have invented a furnace which is simple and economical to manufacture, is sturdily constructed, and provides means for obtaining substantially one hundred per cent combustion of the solid fuel and of the combustible gases driven therefrom, said means being in heat transfer relation with a Warm air duct thereby preventing burning out of said means and also serving to heat the air in the warm air duct. Said means and the warm air duct to which it is attached also cooperate to serve as a wall or bafile for the maga zine 40. Furthermore, the arcuate or semiannular construction of the magazine, grate, com-- bustion chamber, and warm air ducts permits adequate fuel combustion and large heat transfer surfaces while yet permitting the furnace to be of such size as to permit it to pass through any standard doorway of a building.

It will be understood that my nove1 means for introducing secondary air to the combustion chamber and the use of said means together with a fluid containing duct to form a bafile or wall for the magazine may be employed in furnaces or heaters of various constructions, and my invention is not to be limited to the illustrated embodiment, but rather is to be determined by the appended claims.

I claim:

1. In a furnace, in combination, a grate, means forming a combustion chamber above said grate, a magazine for containing a charge of fuel. a slide extending from said magazine to said grate for feeding fuel to the grate, an air inlet duct parially encircling magazine, the inlet end of said duct communicating with the exterior of said furnace, said duct having exit orifices formed therein to permit air to enter the combustion chamber, and flanges on said slide, said duct being supported in part on said flanges.

2. In a furnace, in combination, a grate, means forming a combustion chamber above said grate, a magazine for containing a charge of fuel, a slide extendin from said magazine to said grate for feeding fuel to the grate, a duct positioned above the combustion chamber and being adapted to contain fluid to be heated, an air inlet duct partially encircling said magazine, the inlet end of said inlet duct being in open communication with the exterior of said furnace, said air inlet duct having exit orifices formed therein and positioned above said combustion chamber to supply air to said chamber, and flanges on said slide, said air inlet duct being supported by the fluid containing duct and by said flanges.

3. In a furnace, in combination, a grate, means forming a combustion chamber above said grate, a magazine disposed above said grate for containing a charge of fuel, a slide extending from said magazine to said grate for feeding fuel to the grate, a duct positioned above the combustion chamber and adapted tocontain fluid to be heated, a second duct partially encircling said magazine, the inlet end of said second duct being in open communication with the exterior of said furnace, said second duct having exit orifices formed therein positioned above said combustion chamber and adapted to supply air to said chamber, and flanges on said slide, said second duct being interposed between the grate and the fiuid containing duct in heat transfer relationship with the fluid containing duct, said second duct being supported by said fluid containing duct and said flanges.

4. In a magazine feed furnace adapted to pass through a standard doorway, in combination, a front wall, a substantially arcuate wall joining the ends of said front wall, a bonnet, said two walls together with the bonnet forming the casing of the furnace, a semi-annular grate carried by and disposed in the lower regions of the casing, a, magazine disposed within said casing adjacent said grate and arranged to supply fuel to said grate, means forming a combustion chamber disposed above said grate, means forming two spaced arcuately shaped warm air passageways disposed within said casing, one of said passageways being formed by spaced semi annular walls partially encircling said magazine and the other of said passageways being formed 3y spaced semi-annular Walls disposed radially outwardly from said grate, and a flue disposed above said grate between said passageways and in open communication with said combustion chamber and being defined by adjacent walls of the spaced warm air passageways.

5. In a magazine feed furnace adapted to pass through a standard doorway, in combination, a bonnet, a front wall, a substantially arcuate wall joining the ends of said front wall, said two walls and said bonnet defining a casing for the furnace, means forming a warm air passageway adjacent the arcuate wall, a grate disposed in the lower regions of said casing, means forming a combustion chamber above said grate and adjacent said means forming a warm air passageway, means forming a second warm air passageway spaced from said first warm air passageway, the adiacent walls of said warm air passageways defining between them a flue in open communication with said combustion chamber, and a magazine disposed within said furnace V and adjacent said grate for supplying fuel to said grate, said warm air passageways, grate, combustion chamber, flue and magazine being substantially arcuate and substantially concentric in the order first recited above.

CLEO HARRIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date 113,535 La Rue Apr. 11, 1871 156,821 Ross Nov. 10, 1874 659,971 Hower Oct. 16, 1900 843,106 R0611 Feb. 5, 1907 955,758 Cahoone Apr. 19, 1910 1,121,557 I-Iausfeld Dec. 15, 1914 1,368, 01 Coulston Feb. 15, 1921 1,714,649 Walouke May 28, 1929 2,433,036 Fellows Dec. 23, 1947 

